Safety, Tolerability, Pharmacokinetics of EVP-0962 and Effects of EVP-0962 on Cerebral Spinal Fluid Amyloid Concentrations in Healthy Subjects and in Subjects With Mild Cognitive Impairment or Early Alzheimer's Disease

Inclusion Criteria: * Part 1: Male and female subjects between the ages of 45 to 65 (inclusive) in good health with a BMI of 18-32 kg/m2 and negative urine drug screen of abuse test. * Part 2: Male and female subjects between the ages of 45 to 85 (inclusive), MRI/CT scans compatible with diagnosis of MCI or early AD, meets the classification of MCI due to AD as defined by the National Institute on Aging-Alzheimer's Association, and a BMI of 18-32 kg/m2(inclusive). Subjects must meet the following Cognitive criteria: Subject Memory Complaint, cognitive impairment in one or more areas, CDR-SB score less than or equal 1.0, MMSE greater than 24, and no impairment in social or occupational functioning. Exclusion Criteria: * History of seizure disorder, symptomatic orthostatic hypotension, QTc values greater than 450 ms, positive drug screening tests * Pregnancy, nursing, (or if fertile female) not willing to utilize birth control measures during study * C-SSRS suicidal ideation score of 4 or 5 * Unwilling to abstain from vigorous exercise * Concurrent disease other than MCI or early AD that is attributing to patient's cognitive impairment. * Lumbar spine X-rays show anatomic contraindications to lumbar puncture * History of spinal surgery or chronic low back pain * History of migraine headaches